void main(List<String> arguments) {
  var man = Man();
  man.eat();
  man.walk();
  man.code();

  print("-----------------------");

  var dog = Dog();
  dog.eat();
  dog.walk();
}

class Person {
  say() {
    print("say");
  }
}

mixin Eat {
  eat() {
    print("eat");
  }
}

mixin Walk {
  walk() {
    print("walk");
  }
}

mixin Code {
  code() {
    print("code");
  }
}

class Dog with Eat, Walk {}

class Man extends Person with Eat, Walk, Code {}
